工作于低频段的机载宽波束SAR为了获取高分辨图像,对前向运动误差补偿精度的要求很高。前向运动补偿通常 采用方位向重采样或实时PRF调整,前者的计算量较大,而后者又需要额外的硬件设备。文中提出一种新的适用于机载 宽波束SAR的前向运动补偿算法,利用信号的时频对应关系,在子孔径距离多普勒域中构造相位补偿因子以消除前向运 动误差的影响。算法计算量较小,适合于机载宽波束SAR实时处理。仿真和实测数据处理结果验证了算法的有效性。

Airborne wide-beam synthetic aperture radar (SAR) operating at low frequency band has high request to the accuracy of the along-track motion compensation. There are two conventional compensation approaches based on motion parameters: resample of the azimuth signal and real-time adjustment of the radar pulse repetition frequency (PRF). The former is time consuming and the latter needs extra hardware equipments. A new along-track motion compensation algorithm for airborne wide-beam SAR is proposed in this paper. The algorithm compensates the along-track motion error in the range-Doppler domain of the sub-aperture data by using the time-frequency relationship of the SAR signal. It is fit for real-time processing because of its high efficiency. The effectiveness is validated by using simulated data as well as real-data.